Cutting and shearing tool



Feb. 18, 1941. s, s, C'ZRAIG CUTTING AND SHEARING TOOL Filed March 19, 1940 Patented Feb. 18, 1941 UNITED STATES PATENTFQOFFICE Application March 19, 1940, Serial No. 324,896.

7 Claims. (Cl. 30-- 236) This invention relates to cutlery and more particularly to a tool adapted to perform either shearing or cutting operations by the employment of a single set of cooperating blades.

While cutting tools of various types, adaptable for the performance of a wide variety of operations, are on the market today, there is no known cutting tool, the edges of which are adaptable for shearing as well as cutting. It has heretofore been deemed inexpedient to employ a single tool with a single set of cooperating blades for both cutting and shearing, because of the fact that cutting edges are ordinarily bevel ground or hollow ground to permit a wedge action in cutting while shearing edges are normally ground to define a more or less right angle, two edges cooperating to effect a shear.

Because of the fact that cutting edges have not been considered suitable for shearing operations, the extensive development involving various types of blade holders for the use of discarded razor blades has been limited almost exclusively to the production of additional cutting tools such as paint scrapers, sickles, scythes, etc., while the use of such blades for shearing operations has not been thought feasible.

Furthermore, shears as now known generally have the cooperating blades or edges in a fixed position quite suitable for one particular type of I shear out, such as nipping, but not readily adaptable to the production of different types of shearing actions requiring alterations in the position of the blades to maintain efficiency regardless of the location and character of the material It is an object of this invention to provide a tool consisting of cooperating blade holders by the use of which discarded razor blades or other beveled ground cutting edges may be employed with equal facility for both shearing and cutting operations, thereby enormously increasing the field of use for discarded razor blades.

Furthermore, the present invention contemplates the mounting of cutting edges in such a 7 way that shearing and nipping operations may be performed by a simple adjustment of a single tool, while by further adjustment of the tool cutting operations such as ripping and scraping may be performed.

By the employment of the present invention, either cutting or shearing operations may be performed in cooperation with means for guiding the cutting edges, while such means are so positioned and arranged as to avoid the slightest interference with either type of operation. This invention now makes it possible to begin a cutting operation by the-use of a shearing action which may be followed by a cutting action without any adjustment whatsoever of the tool employed. I

According to the present invention, the blades are mounted in holders from which they may be easily removed for either replacement or sharpening, thus permiting the use of discarded razor blades. Thus in the trimming of shrubbery, neat, sharp shearing is possible so that wounds to the vegetation may heal more readily while the pruning operations, from the standpoint of the operator, are more easily performed.

It is further within the contemplation of the present invention to provide a superior shearing tool, the edges of which may be readily adjusted into various working positions thereby contributing to the efficiency of the tool and the convenience of the operator.

Other objects. and-advantages of this invention will be apparent from a consideration of the following detailed description. of a preferred embodiment thereof when taken in conjunction with the annexedv drawing wherein:

Figure 1V is a view inside elevation of the device showingthe cutting edges operating. in a plane. parallel to the longitudinal axis of the holders;

Figure 2 is a plan view'of the device in the adjusted position employed for combined shearing and ripping;

Figure 3 is a sligh device showing the Figure 2; and s Figure 4 is a detail view showing the pin slots in a support arm, a friction disc, and an L-piece.

Referring in further detail to the drawing, the tool comprises support members l and II which extend from a spring pivot l2 in the manner of conventional grass shears, and L-piece l3 attached to each support member, and a blade holder l4 and blade l5 connected to respective L-pieces.

While two L-pieces are used, the L-piece adjacent support member II is affixed thereto in the same manner as that which is attached to support member In, so that a description of the manner of afiixation of the latter will apply with equal force to both.

It will be noted upon reference to Figure 4, that support member [0 and a shank 16 of L-piece l3 are provided with cooperating apertures l1 and I8 respectively. Aperture I! is elongated in the direction of the longitudinal axis y. enlarged end view of the blades in the position of of member Ill while aperture I8 is elongated in the direction of the longitudinal axis of shank I6. When the tool is assembled these apertures are placed in alignment and a threaded bolt I9 is passed therethrough while thumb nut 29 is tightened to lock the shank I6 and arm I0 against relative movement about bolt 19 as an axis.

Since L-piece I3 is attached to support member I 0 and since it also has attached thereto blade I5, it is important that means he provided for holding L-piece I3 in any adjusted position with regard to support member Ill. Consequently, it is desirable that the end of support member I0 and the shank I6 of L-piece I3 be rounded and slightly enlarged so as topresent a large friction area. The disposition of a radially scored friction disc 2I between shank I6 and support member I9 further assists in frictionally locking said pieces against relative movement when nut 20 is tightened. As shown in Figure 4, friction disc 2I is drilled at 22 to receive stud I9.

A blade holder I4 is attached to shank 23 of each L-piece I3 which shank is drilled at 24 for the reception of a stud and is rounded so as not to interfere with the cutting edge of blade I5 when it is clamped in holder I4. The blade holders I4 each consist of a member 25 having a stud 26 extending therefrom and a cooperating member 2I adapted to overlie member 25 to clamp blade I5 therebetween. In attaching the blade holder I4 to shank 23, stud 25 is passed through aperture 24 and a thumb nut 28 is attached to hold the parts against pivotal movement about stud 26 as an axis. As illustrated in Figure 3 a washer or bushing 29 may be interposed between member 25 and shank 23, although if desired member 25 may rest directly against the surface of shank 23.

Members 25 and 21, which constitute blade holder I4, are each provided with a longitudinal groove to constitute a receiving recess for a razor blade backing in the event it is desired to use a razor blade of that type. If a double edge blade is employed screws 39, which are employed in holding together members 25 and 21 to frictionally grip a blade therebetween, may function to prevent the blade from being thrust too far into the holder so that the cutting edge is no longer exposed. In the preferred form shown, screws 38 are seated in member 25 for rotation while they are threaded to cooperate with threaded apertures in member 21 to draw the latter against member 25 upon turning the screws 30.

Supporting arms I0 and II are provided with aligned apertures somewhat nearer pivot I2 than the blades and a bolt 3| is passed through these apertures. Bolt 3| has a threaded shank 32 on which a thumb nut 33 is mounted so that the arms I8 and II may be held against movement apart in any desired position. This bolt will also function to a certain extent in keeping the arms II] and II in the same plane as they are moved about spring pivot I2. However, due to the fact that a very accurate adjustment of the blades is necessary in performing shearing operations a tongue 34 extends from support member I 0 and is received in a housing 35 U in cross-section in aligned position extending from member I I. This arrangement will keep the two members In and I I in exactly the same plane during shearing operations even when heavy materials are being severed.

Bolt 3I is centrally drilled at 36 and extending through the opening is a graduated guide rule 31 having a line follower 38 thereon. A set screw 39 is threaded into bolt 3| so as to cooperate with rule 31 in its passage through aperture 36. By the use of screw 39 follower 38 may be frictionally locked at any given distance from bolt 3I and consequently from blades I5. Additionally guide 37 may take a wide variety of radial positions as regards bolt 3|, for example see Figure 1 both the full and broken lines.

When the preferred form of this invention as described above and as illustrated in the annexed drawing is to be used, the operator first determines the plane in which he wishes blades I 5 to lie. Thereafter thumb nuts 20 are loosened and the blade holders I4 with the blades I5 therein are adjusted to any desired position generally tangent to the rounded portions of supporting members if! and II by mere pivotal movement of L-pieces !3. In the event a shearing operation is to be performed an additional adjustment will be necessary as regards one of the L-pieces I3. This latter adjustment involves the use of slot I8 whereby one L-piece I3 and its accompanying blade I 5 may be adjusted to lie in a plane parallel to the plane of the cooperating blade but slightly offset with respect thereto so that the beveled edges of the two blades may cooperate in producing a shear out. (See Figure 3.) When these, two adjustments are complete thumb nut 20 is tightened to frictionally lock each shank I6 and friction disc 2I against rotation with regard to its respective support member.

During the foregoing adjustment the edges of the blades are presumably parallel as well as the blade bodies lying in parallel planes. Under some conditions adjustment of the angle defined between the two blades when they are drawn together may be desirable. To perform this adjustment thumb nuts 28 are loosened and the blade holders I4 are pivotally moved about their respective studs 26 until the desired blade positions are reached. Thereafter nuts 28 are tightened.

One example of the many possible uses of the invention is to be found in Figure 2 wherein the blades are set for a shear cut but are locked against movement apart by bolt and nut connection 3!33. The angular position of the blade edges with respect to each other is such that in cutting material such as rubber sheeting an initial or starting out may be made by a shearing action while thereafter ripping may be efiected by merely pushing the device toward the material with follower 38 contacting the line along which the cut is to be made to guide the operator.

If a draw out is desired the edges of the blades may be set close together at their outer rather than their inner ends while the blade assembly as a whole may be offset from the handles by the use of the elongated apertures I1 and I8. The tool is then used by being drawn toward the operator.

It should be borne in mind that the foregoing description is merely exemplary and that many modifications of the device may be made within the scope and spirit of the appended claims. For example, the pivot I2 may be in the form of a hinge while the spring action is attainable by the use of a coil spring positioned between members I0 and II. While single cooperating blades have been shown it will be recognized that the employment of a plurality of such blades is within the scope of this invention.

What is claimed is:

1. A cutting tool comprising, p-ivotally mounted support members, an L-piece pivotally attached to each member with the free ends of the Us facing, blades, a support for each blade, means pivotally connecting a support to respective free ends of L-pieces, and means for locking the pivoted parts against pivotal movement.

2. A combined cutting and shearing device comprising, pivotally mounted support members, an L-piece pivotally attached to each member with the free ends of the Us facing, razor blades, a support for each razor blade, means pivotally connecting a support to respective free ends of L-pieces, means for locking said pivoted parts againstpivotal movement, and means for adjusting the position of a blade and support with respect to the axis of pivotal movement of said support.

3. A combined cutting and shearing device comprising, pivotally mounted support members, an L-piece pivotally attached to each member with the free ends of the Us facing, razor blades, a support for each razor blade, means pivotally connecting a support to respective free ends of the L-pieces, means for locking said pivoted parts against pivotal movement, means associated with said support members for holding said blades against movement apart and means connected to said last-named means adapted to act as a guide during ripping operation, said guide means and the means to which it is attached lying in the same plane as the point of pivot of said support members and their respective L-pieces.

4. A cutting device comprising, pivotally mounted-support members, a secondary support pivotally attached to each member, means defining an axis of pivotal movement, blades pivotally attached to said secondary support, and means defining an axis of pivotal movement as regards said blades and said secondary supports, said first and second-named axes being at right angles to each other.

5. A device according to claim 4 and including means for adjusting the position of the blade with respect to the axis of pivotal movement of a support member and a secondary support member.

6. A combined cutting and shearing tool comprising, pivotally mounted support members, razor blades extending from said support members with their edges facing, and means for adjusting one of the blades to lie in a plane parallel to but slightly offset with respect to another, whereby a shearing action may be had by the use of beveled edge razor blades.

7. A combined cutting and shearing tool comprising, pivotally mounted support members, means to maintain the support members in the same plane when they are pivotally moved in a shearing operation, razor blades extending from said support members with their edges facing, and means for adjusting one of the blades to lie in a plane parallel to but slightly ofiset with respect to another, whereby a shearing action may be had by the use of beveled edge razor blades.

SAMUEL SHARPE' CRAIG. 

